1. Field of the Invention
The present invention relates to a blade material for a metallic band saw which is used for cutting metallic materials and like materials, and more particularly to a blade material comprising high-speed steel and used for a metallic band saw having a body material and a blade material joined in parallel to the body material; and to a metallic band saw made therefrom.
2. Description of the Related Art
Most metallic band saws used for cutting metallic materials and like materials are constructed of a body material exhibiting toughness and a blade material comprising, for example, high-speed steel exhibiting high hardness, wherein the blade material is joined in parallel to the body material. Blade materials for such a metallic band saw include SKH59 (equivalent to AISI M42, DIN W Nr 13247, SS SWEDEN 2716 and AFNOR HS2-9-1-8 Z110DKCWV09-08-04-02-01) and SKH51 ( equivalent to AISI M2, DIN W Nr 13343, SS SWEDEN 2722 and AFNOR HS6-5-2 Z85WDCV06-05-04-02). SKH59 is mainly used to cut cutting-resistant materials such as SKD11 (equivalent to AISI D2, DIN 12379, SS SWEDEN 2310 and AFNOR X160CrMoV12 Z160CDV12) and stainless steel, and SKH51 is used for cutting, for example, structural steel. As compared with SKH51, SKH59 contains an additive of Co, and in addition, a slightly greater amount of a W equivalent (W+2Mo), to thereby attain enhanced heat resistance and wear resistance, and finds use in cutting cutting-resistant materials. However, the cutting edge of a metallic band saw made of SKH59 undergoes considerable wear when used to cut cutting-resistant materials, and thus is not completely satisfactory.
In order to reduce wear of the cutting edge, a V-rich high-speed steel has been used as a blade material. Although addition of a large amount of V (vanadium) provides reduced wear of the cutting edge, it sometimes leads to chipping of the cutting edge, thereby limiting the service life of the blade.
Chipping of a cutting edge has been elucidated to be caused by hard and large carbide grains precipitated in the blade material. Particularly, a high V content permits formation of hard and large carbide grains, and due to the attendant reduction of C content in the matrix, hardness of the matrix decreases to thereby simultaneously cause deterioration in wear resistance of the matrix.